binary_s

#include<bits/stdc++.h>
using namespace std;
int a[1000];
int binary(int key,int n)
{
    int ends,beg,index,mid;
    ends=n-1;
    beg=0;
    index= -1;
    while(beg<=ends)
    {
        mid = (beg + ends)/2;
        if(key == a[mid])
        {
            index=mid;
            cout<<index<<endl;
            break;
        }
        else if(key < a[mid])
        {
            ends = mid-1;
            cout<<ends<<endl;
            cout<<index<<endl;
        }
        else if(key > a[mid])
        {
            beg = mid+1;
            cout<<beg<<endl;
            cout<<index<<endl;
        }


    }
    return index;


}
int main()
{
    int n,i,j,k,mid,key=23;
    cin>>n;
    for(i=1; i<=n; i++)
    {
        cin>>a[i];

    }
    cout<< binary(key,n);

    return 0;
}